The invention relates to a device for removing the noxious and aromatic substances from an air flow fed into the interior of a vehicle. The device comprises an air feed housing in which at least one reactor is disposed that absorbs the noxious and aromatic substances.
DE 35 32 463 A1 discloses an air-conditioning system for a motor vehicle in which a dust filter and an odor filter are disposed in an air feed duct. Such odor filters comprise materials which absorb the aromatic substances because of their surface structure. Since the adsorption power of such filters is limited, the adsorption power decreases as time progresses and some of the substances deposited are liberated again and fed again into the interior of the vehicle by the air flow. After a specified operating time, these filter elements have to be replaced. So that the servicing intervals do not become too short, such filters have to be of appropriately large design in regard to the volume and/or the packing density, which is disadvantageous in regard to the installation space required or the pressure loss which occurs. In addition, only a few types of odorous or noxious substances are dealt with by the known filters.
DE 35 17 105 C1 describes a method for continuously removing noxious substances from a gas flow. For this purpose, a drum is provided which is filled with an absorbent, in which the gas to be purified enters through a pipe and to which there are connected two pipes through which the gas leaves. No defined air flows are formed in the drum, with the result that the exposure of the individual zones is essentially dependent on the flow resistances within the absorbent and at the outgoing pipes. Because of the bulk density in the drum, high pressure losses are produced, with the result that a high expenditure of energy is necessary to generate the gas flow. In addition, to desorb the reactor material, the gas flow component which has taken up the desorbed noxious substances has to be fed through the entire reactor to the appropriate outgoing pipe in the known arrangement.
DE 40 23 995 C2 discloses a device for fresh-air and interior-air purification in motor vehicles by means of a photocatalyst which is irradiated with photons and has a semiconductor base. To operate such a device, a mercury-vapor lamp which is attached using spring means to the catalyst bed fixed to the vehicle is required as radiation source.
DE 35 45 664 A1 describes a ventilation device for the cabin of an agricultural vehicle which comprises a fan and a plurality of filters. In this case, a first filter is designed as dust filter and a second filter as liquid trap. The third filter is a reactor for removing toxic substances in the intake air. Said filter is designed as a flat wall and is disposed in an air flow path upstream of the driver's cabin. The air-flow direction through the reactor can be reversed with the aid of multiway valves, one of the flow directions being provided for adsorption operation and the other flow direction for the desorption operation of the reactor.